Pub Date : 2019-11-01DOI: 10.1109/IRMMW-THz.2019.8873730
Di Liu, A. Pronin, A. Markou, C. Felser, M. Dressel
Coherent-source THz spectroscopy was employed for measuring the Faraday rotation angle of Mn$_{mathbf {2-x}}$PtSn films (x $=$ 0; 0.2). In the THz experiments, we observe clear signatures of an anomalous Hall state, while any indications of the so-called topological Hall effect recently observed in these magnetically disordered systems in dc measurements - are absent. This demonstrates that the charge scattering mechanisms, responsible for the two phenomena, possess very different time scales: the anomalous Hall state is governed by the scattering process with the rates above THz frequencies, while the electron interaction, providing the topological Hall, possesses very low characteristic time scales.
{"title":"Terahertz Anomalous Hall Effect in Mn2-xPtSn","authors":"Di Liu, A. Pronin, A. Markou, C. Felser, M. Dressel","doi":"10.1109/IRMMW-THz.2019.8873730","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8873730","url":null,"abstract":"Coherent-source THz spectroscopy was employed for measuring the Faraday rotation angle of Mn$_{mathbf {2-x}}$PtSn films (x $=$ 0; 0.2). In the THz experiments, we observe clear signatures of an anomalous Hall state, while any indications of the so-called topological Hall effect recently observed in these magnetically disordered systems in dc measurements - are absent. This demonstrates that the charge scattering mechanisms, responsible for the two phenomena, possess very different time scales: the anomalous Hall state is governed by the scattering process with the rates above THz frequencies, while the electron interaction, providing the topological Hall, possesses very low characteristic time scales.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"18 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74085074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8874191
Rupa Basu, L. R. Billa, Jeevan M. Rao, R. Letizia, C. Paoloni
The design and fabrication aspects of a novel D-band (141 GHz-148.5 GHz) Traveling Wave Tube (TWT) for enabling the first point to multipoint front end at D-band, objective of European Commission H2020 ULTRAWAVE is presented. The ULTRAWAVE system will provide unprecedented wireless area capacity over wide area sectors, with radius up to 500 – 600 m for the future 5G high density small cell deployment. The design and fabrication processes adopted for the TWT are focused to find new low cost solutions for TWTs at millimetre waves to satisfy the requirements of the wireless market. The proposed TWT will provide more than 10 W saturated output power for achieving more than 100 Gb/s/km2 of area capacity over 600 meters radius wide angle sector, with 99.99% availability in ITU zone K.
{"title":"Design and fabrication of a D-Band Traveling Wave Tube for millimeter wave communications","authors":"Rupa Basu, L. R. Billa, Jeevan M. Rao, R. Letizia, C. Paoloni","doi":"10.1109/IRMMW-THz.2019.8874191","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874191","url":null,"abstract":"The design and fabrication aspects of a novel D-band (141 GHz-148.5 GHz) Traveling Wave Tube (TWT) for enabling the first point to multipoint front end at D-band, objective of European Commission H2020 ULTRAWAVE is presented. The ULTRAWAVE system will provide unprecedented wireless area capacity over wide area sectors, with radius up to 500 – 600 m for the future 5G high density small cell deployment. The design and fabrication processes adopted for the TWT are focused to find new low cost solutions for TWTs at millimetre waves to satisfy the requirements of the wireless market. The proposed TWT will provide more than 10 W saturated output power for achieving more than 100 Gb/s/km2 of area capacity over 600 meters radius wide angle sector, with 99.99% availability in ITU zone K.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"46 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85985028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8874220
J. Song, S. Engelbrecht, B. Fischer, Hungyen Lin
An adaptive windowing short-time Fourier transform algorithm is proposed where the width of short-time window is adaptively adjusted based on the frequencies of interest. The algorithm is then applied to lactose measurements acquired using THz-TDS and compared against the standard fixed window spectrogram where improved spectral contrast is observed.
{"title":"Short-time Fourier Transform with Adaptive Windowing Size for THz-TDS","authors":"J. Song, S. Engelbrecht, B. Fischer, Hungyen Lin","doi":"10.1109/IRMMW-THz.2019.8874220","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874220","url":null,"abstract":"An adaptive windowing short-time Fourier transform algorithm is proposed where the width of short-time window is adaptively adjusted based on the frequencies of interest. The algorithm is then applied to lactose measurements acquired using THz-TDS and compared against the standard fixed window spectrogram where improved spectral contrast is observed.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"68 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84169032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8874277
D. Lake, E. Snedden, D. Walsh, D. Graham, S. Jamison
The temporal and spatial evolution of single-cycle THz pulses travelling across a dielectric boundary with effective surface velocity below $c$ has been examined. The resulting subluminal evanescent waves in the near field vacuum region are potential drivers of particle accelerators. The electro-optic temporal and spatial imaging of the THz pulses emitted from the surface were measured in the near field, as a function of distance from the dielectric boundary, and reveal both temporal broadening and field decay that is dependent on the effective velocity of the wave in the plane of the boundary.
{"title":"Spatial and Temporal Field Evolution of Evanescent Single-Cycle THz Pulses","authors":"D. Lake, E. Snedden, D. Walsh, D. Graham, S. Jamison","doi":"10.1109/IRMMW-THz.2019.8874277","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874277","url":null,"abstract":"The temporal and spatial evolution of single-cycle THz pulses travelling across a dielectric boundary with effective surface velocity below $c$ has been examined. The resulting subluminal evanescent waves in the near field vacuum region are potential drivers of particle accelerators. The electro-optic temporal and spatial imaging of the THz pulses emitted from the surface were measured in the near field, as a function of distance from the dielectric boundary, and reveal both temporal broadening and field decay that is dependent on the effective velocity of the wave in the plane of the boundary.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"38 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74583131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8873748
B. Benakaprasad, A. Eblabla, X. Li, K. Elgaid
We demonstrate a quadrature branch-line coupler operating at 90 GHz on GaN-on-low resistivity silicon substrates $(rho lt 40 Omega cm$). To reduce the losses offered by the low-resistivity silicon at 90 GHz, a shielding technique is used where the silicon substrate is covered by a ground plane (Al metal). SiO2 dielectric of thickness $10 mu mathrm{m}$ is used as a spacer between the top metal and ground plane to further improve the performance of the coupler. Measured results showed return loss and isolation as low as -25 dB and -16 dB respectively, and coupling loss of $-4 pm 0.5$ dB from 81 GHz to 101 GHz. The output amplitude imbalance achieved was less than 1 dB. The coupler validates the shielding MMIC technology on GaN-on-low resistivity silicon substrate.
{"title":"90 GHz Branch-line Coupler on GaN-on-Low Resistivity Silicon for MMIC Technology","authors":"B. Benakaprasad, A. Eblabla, X. Li, K. Elgaid","doi":"10.1109/IRMMW-THz.2019.8873748","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8873748","url":null,"abstract":"We demonstrate a quadrature branch-line coupler operating at 90 GHz on GaN-on-low resistivity silicon substrates $(rho lt 40 Omega cm$). To reduce the losses offered by the low-resistivity silicon at 90 GHz, a shielding technique is used where the silicon substrate is covered by a ground plane (Al metal). SiO2 dielectric of thickness $10 mu mathrm{m}$ is used as a spacer between the top metal and ground plane to further improve the performance of the coupler. Measured results showed return loss and isolation as low as -25 dB and -16 dB respectively, and coupling loss of $-4 pm 0.5$ dB from 81 GHz to 101 GHz. The output amplitude imbalance achieved was less than 1 dB. The coupler validates the shielding MMIC technology on GaN-on-low resistivity silicon substrate.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"6 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90981945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8874517
Liang Zhang, C. Donaldson, Wenlong He, A. Phelps, A. Cross
A terahertz gyrotron traveling wave amplifier (gyro-TWA) centered at 370GHz is under development for the electron paramagnetic resonance (EPR) imaging application. This paper reports the investigation of a triode-type cusp electron gun for the terahertz gyro-TWA. The simulation results showed that at the beam alpha (the ratio of transverse to axial velocity) center of 1.07, an optimal alpha spread of $sim 10%$ was achieved, when it was operated at a beam voltage of 50 kV and a beam current of 0.35 A.
{"title":"Cusp electron gun with modulation electrode for a THz gyro-amplifier","authors":"Liang Zhang, C. Donaldson, Wenlong He, A. Phelps, A. Cross","doi":"10.1109/IRMMW-THz.2019.8874517","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874517","url":null,"abstract":"A terahertz gyrotron traveling wave amplifier (gyro-TWA) centered at 370GHz is under development for the electron paramagnetic resonance (EPR) imaging application. This paper reports the investigation of a triode-type cusp electron gun for the terahertz gyro-TWA. The simulation results showed that at the beam alpha (the ratio of transverse to axial velocity) center of 1.07, an optimal alpha spread of $sim 10%$ was achieved, when it was operated at a beam voltage of 50 kV and a beam current of 0.35 A.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"28 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88874125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/irmmw-thz.2019.8874384
T. Akalin, A. Chahadih, Ibrahim Türer, M. Navarro‐Cía, M. Beruete, A. Ghaddar
We have fabricated a terahertz source based on the combination of an integrated Uni-Travelling-Carrier Photodiode (UTC-PD) and a leaky wave antenna. The UTC-PD is a broadband source and we have used an efficient transition from CPW to Planar Goubau Line (PGL). In this PGL section, we have included complementary Split Ring Resonators (c-SRR) in order to obtain a leaky wave antenna (LWA). The broadband behavior of the source and of the transition allow us to design systems at a given frequency range by modifying only the c-SRR along the PGL.
{"title":"Combined UTC-PD integrated THz source and a leaky wave antenna with complementary split ring resonators along a planar Goubau line","authors":"T. Akalin, A. Chahadih, Ibrahim Türer, M. Navarro‐Cía, M. Beruete, A. Ghaddar","doi":"10.1109/irmmw-thz.2019.8874384","DOIUrl":"https://doi.org/10.1109/irmmw-thz.2019.8874384","url":null,"abstract":"We have fabricated a terahertz source based on the combination of an integrated Uni-Travelling-Carrier Photodiode (UTC-PD) and a leaky wave antenna. The UTC-PD is a broadband source and we have used an efficient transition from CPW to Planar Goubau Line (PGL). In this PGL section, we have included complementary Split Ring Resonators (c-SRR) in order to obtain a leaky wave antenna (LWA). The broadband behavior of the source and of the transition allow us to design systems at a given frequency range by modifying only the c-SRR along the PGL.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"1 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88661052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8874369
V. Balos, M. Wolf, M. Sajadi
We study the impact of highly charged ions on the local structural deformation of the hydrogen-bonding network of liquid water by means of dynamic Terahertz (THz) Kerr effect (TKE). By a systematic variation of anionic vs cationic charge density of the selected ions, we discover a correlation between the ionic charge density to the strengthening or weakening of the coupling between the rotational and the translational motions in water. The latter intermolecular probe, clearly shows opposite anionic versus cationic effect and enables us to provide a novel insight on the structure making / breaking behavior of ions.
{"title":"Intermolecular Probe for the Structural Deformation of Liquid Water Around Highly Charged Ions","authors":"V. Balos, M. Wolf, M. Sajadi","doi":"10.1109/IRMMW-THz.2019.8874369","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874369","url":null,"abstract":"We study the impact of highly charged ions on the local structural deformation of the hydrogen-bonding network of liquid water by means of dynamic Terahertz (THz) Kerr effect (TKE). By a systematic variation of anionic vs cationic charge density of the selected ions, we discover a correlation between the ionic charge density to the strengthening or weakening of the coupling between the rotational and the translational motions in water. The latter intermolecular probe, clearly shows opposite anionic versus cationic effect and enables us to provide a novel insight on the structure making / breaking behavior of ions.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"58 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84123744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/IRMMW-THz.2019.8874140
V. Georgiadis, M. Hibberd, A. Healy, D. Lake, G. Burt, S. Jamison, D. Graham
We report on the generation of a terahertz (THz) beam with a quasi-TEM01 mode by exploiting the interferometric recombination of two linearly polarized emitters in a combined spintronic source. The generated THz beam was used to characterize the accelerating mode of a dielectric-lined waveguide (DLW) to inform on the recent demonstration of relativistic electron beam manipulation achieved with this THz-driven DLW at the CLARA research facility at Daresbury Laboratory.
{"title":"Characterizing the accelerating mode of a dielectric-lined waveguide designed for terahertz-driven manipulation of relativistic electron beams","authors":"V. Georgiadis, M. Hibberd, A. Healy, D. Lake, G. Burt, S. Jamison, D. Graham","doi":"10.1109/IRMMW-THz.2019.8874140","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874140","url":null,"abstract":"We report on the generation of a terahertz (THz) beam with a quasi-TEM01 mode by exploiting the interferometric recombination of two linearly polarized emitters in a combined spintronic source. The generated THz beam was used to characterize the accelerating mode of a dielectric-lined waveguide (DLW) to inform on the recent demonstration of relativistic electron beam manipulation achieved with this THz-driven DLW at the CLARA research facility at Daresbury Laboratory.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"32 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80048187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-21DOI: 10.1109/irmmw-thz.2019.8874311
C. Paoloni, S. Boppel, V. Krozer, R. Letizia, E. Limiti, F. Magne, Marc Marilier, A. Ramírez, B. Vidal, Trung Le, R. Zimmerman
The first point to multipoint wireless system at D-band (141 - 148.5 GHz), providing high capacity area sectors fed by high data rate G-band (275 - 305 GHz) links connected to fiber access points, will be described. It is the objective of the European Commission H2020 ULTRAWAVE “Ultra capacity wireless layer beyond 100 GHz based on millimeter wave Traveling Wave Tubes”. The high transmission power provided by novel millimeter wave traveling wave tube will allow an unprecedented range and data rate at this frequency band. A novel MMIC chipset including components built by GaAs and InP processes to realize a full electronics solution for the sub-THz wireless communication system will be described.
{"title":"Sub-THz components for high capacity point to multipoint wireless networks","authors":"C. Paoloni, S. Boppel, V. Krozer, R. Letizia, E. Limiti, F. Magne, Marc Marilier, A. Ramírez, B. Vidal, Trung Le, R. Zimmerman","doi":"10.1109/irmmw-thz.2019.8874311","DOIUrl":"https://doi.org/10.1109/irmmw-thz.2019.8874311","url":null,"abstract":"The first point to multipoint wireless system at D-band (141 - 148.5 GHz), providing high capacity area sectors fed by high data rate G-band (275 - 305 GHz) links connected to fiber access points, will be described. It is the objective of the European Commission H2020 ULTRAWAVE “Ultra capacity wireless layer beyond 100 GHz based on millimeter wave Traveling Wave Tubes”. The high transmission power provided by novel millimeter wave traveling wave tube will allow an unprecedented range and data rate at this frequency band. A novel MMIC chipset including components built by GaAs and InP processes to realize a full electronics solution for the sub-THz wireless communication system will be described.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"234 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80319565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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